Continuous filtration centrifuge



CONTINUOUS F ILTRAT ION CENTRIFUGE 0. fan /fn /a uw INVENTOR.

BX MMM Wj April 29, 1969 J. PINKAVA l 3,441,144

CONTINUOUS FILTRATION .CENTRIFUGE l Filed sept. 27, 1968 sheet 2 of 2 llif l" s? ff- United States Patent O Ceskoslovenska akademie ved, Prague, Czechoslovakia Filed Sept. 27, 1968, Ser. No. 763,091 Claims priority, application Czechoslovakia, Sept. 29, 1967, 6,932/ 67, 6,933/ 67 Int. Cl. B01d 29/26, 29/10, 33/04 U.S. Cl. 210-370 3 Claims ABSTRACT OF THE DISCLOSURE A filtration centrifuge, comprising open-ended ribbed inner and outer drums, the ribs of the inner drum being between the ribs of the outer drum so that said inner drum is `driven by said outer drum, each drum havin-g a hollow shaft, the shaft of the inner drum extending through the shaft of the outer drum, the axis of said drums being skewed so that a rope introduced through the inner hollow shaft is wound at the internal surface of both drums in a helical path to form a filter surface inside said drums, at least one of said drums provided on its open end with internal radial extensions.

This invention relates to improvements of a continuous filtration centrifuge which is the object of the U.S. Patent No. 3,358,840.

This centrifuge consists of two open-ended drums, whose cylindrical surfaces are made of individual ri-bs parallel with the drum axes, which engage into each other, so that if one drum rotates, it carries along the other drum which is thus also rotated. The shafts of both `drums are hollow, the shaft of the second drum passes through the shaft of the first drum whereby the axis of both drums are skewed. The hollow shaft of the second drum guides a rope inside the drum, which rope is due to centrifugal force deposited on the internal surface of both drums in the form of helical turns and is withdrawn from the open ends of the drums, whereby it slowly proceeds from one end of the drums to the other.

The withdrawn rope is cleaned outside the centrifuge to be again returned to the centrifuge through the hollow shafts.

The density of the helical turns of the rope, forming the filter layer depends on the speed with which said rope is supplied, on the number of revolutions of the drums and on the relative inclination of the axis of both drums. By adjustment of any of said values the helical turns may be deposited either rather loosely, or very close, or a multilayer filter may be achieved. Closely Iadjacent single layer turns have proved to be most advantageous in operation. It happens however, that a gap is occasionally formed between two adjacent turns, through which gap particles of the filtered suspension can pass, so that the resulting filtrate is of inferior quality. A reduction of the angle of inclination of both drum axes causes a reduced forward movement of the rope turns or an increased supply speed of the rope leads generally to the creation of a two layer filter.

It is an object of this invention to eliminate said drawback, by the provision of internal radial extensions at the open end of at least one of said drums.

The invention will be best understood from the following specification to be read in conjunction with the accompanying drawings in which FIG. l is a longitudinal sectional view of the centrifuge;

3,441,144 Patented Apr. 29, 1969 FIG. 2 is an enlarged view of the ribs of the drums in FIG. 1; and

FIG. 3 is an alternative embodiment of extensions according to this invention.

Referring now particularly to FIGS. l and 2, drums 1 and 2, open on one side, are mounted on shafts `4 and 4', which shafts are not parallel. The cylindrical surfaces of both drums 1 and 2 are made of individual ribs 5 and 6 which are parallel with the :axis of the respective drums 1 and 2 and enga-ge into each other, as shown in FIG. 2. Therefore if the drum 1 with the ribs 5 rotates, it carries along the ribs 6 of the drum 2 which is also rotated. The shaft 4 of the drum 1 is mounted in the stationary bearing 7 which is connected with the casing 2'9 of the centrifuge. Both shafts 4 and 4 are hollow, the shaft 4 of the drum 2 passing through the shaft 4 of drum 1. The shaft 4 is mounted 4within the hollow shaft 4 -by means of the bearing v8 enabling an adjustment of the relative angular position of both shafts 4, 4. The shaft 4 is furthermore provided with a stationary mounted ring 9, against which rests on one side a micrometric screw 10 and on the other side a spring 11. The shaft 4 of drum 1 is provided on its end with a pulley 12 for driving this drum.

The rope 413 which forms the filter layer 20 is supplied to the interior of both drums via the hollow shaft 4' by Way of the roller 15 from a not shown winding and cleaning device. Due to the action of centrifugal force, this rope 13 is deposited in helical turns at the internal surface of both drums 1, 2 forming a continuous filter layer 20, which proceeds due to the relative inclination of both drums 1, 2 slowly from one end of the drums 1, 2 to the other, whereby the rope 13 is at the open end withdrawn through the tube 22 laying in the axis of shaft 4 via the roller 16 to the not shown winding and cleaning device, to be again returned cleaned into the interior of both drums 1, 2. In the alternative shown in FIG. 1 the ribs 5 extend beyond the ribs `6 `and terminate in a ring provided with a groove, into which a guiding ring 14 is inserted which extends radially beyond the interior surface of the drum 1. The turns of the rope 13 are uniformly pressed against this ring 14 by the whole filter layer 20 proceeding slowly from one end of the drums 1, 2 to the other, safeguarding that the individual turns of the rope 13 are close one to the other.

It is obvious that instead of the inserted ring 14 the ring may be arranged so as to extend radially beyond the internal surface of the ribs 5. Another possibility shown in FIG. 3 is to fix at the internal ends of ribs 5 short bolts 14 which have the same effect as the ring 14 from FIG. 1. In that `case no ring is provided and both ribs 5 and 46 may be of equal length.

I claim:

1. A continuous filtration centrifuge, comprising an outer drum :and an inner drum inserted in the said outer drum, -both said drums open at one end;

the envelopes of said two drums each comprising a plurality of parallel ribs, the ribs of one drum enga-ging between ribs of the other ldrum;

the axis of both drums arranged with respect to each other in directions different from parallel;

a hollow shaft on said outer drum;

la hollow shaft on said inner drum, mounted in the said hollow shaft of the said outer drum;

means for feeding an endless rope into the interior of said drums through said hollow shafts;

means for removal of said rope on the open end of said drums;

a jet through which a suspension can be injected into the inner space of said two drums into a filtration layer formed in consequence of the continuous rope being wound by action of the centrifugal force of ICC the running centrifuge over the inner surface of the References Cited said drums in the form of helical turns; and

extensions on the open end of at least one of said UNITED STATES PATENTS drums, extending radially beyond the interior surface 3,358,840 12/1967 Pmkava 210*370 of said drum.

2. A continuous filtration centrifuge as claimed in 5 REUBEN FRIEDMAN Pumary Examine"- claim 1 wherein said extensions are in the form of a ring. L DECESARE Assistant Examine,.

3. A continuous filtration centrifuge as claimed in claim 1 wherein Said extensions are in the form of bolts U.S. Cl. X.R.

inserted into said ribs forming the envelope of the drum. 10 ZIO- 380, 497.1 

